"She is the defending champion and she has a great record of grass-court tennis - it's obviously one of her better surfaces," Wimbledon referee Alan Mills told The Associated Press.

"It's the same for Venus," he added. "We are basically thinking in terms of the grass courts and the records of the players. That's why we went with that."

The seedings were more straightforward for the men, with the top four following the rankings.

Defending champion and top-ranked Roger Federer is No. 1, followed by Andy Roddick. Guillermo Coria, who lost in the French Open final, is No. 3, with 2002 Wimbledon runner-up David Nalbandian at No. 4.

Britain's Tim Henman was bumped up from sixth in the rankings to No. 5 in the seedings. Spain's Juan Carlos Ferrero dropped from fifth to sixth.

Lleyton Hewitt, the 2002 champion, was seeded at No. 7 - three places above his ranking. Andre Agassi, the 1992 champion who is ranked No. 9, pulled out Tuesday with a hip injury.

The women's field is wide open after last week's withdrawals of Henin-Hardenne (viral illness) and Clijsters (wrist injury).

Amelie Mauresmo is seeded No. 4, followed by Lindsay Davenport, French Open runner-up Elena Dementieva and Jennifer Capriati.

The Williams sisters both lost in the quarterfinals of the French Open and have slipped steadily in the rankings. Last week, Serena was No. 11, out of the top 10 for the first time in five years.

During one stretch, the sisters won eight of 11 Grand Slam tournaments. But Venus last won a Slam in 2001, and Serena hasn't been in a major final since last year's Wimbledon.

Serena had surgery on her left knee Aug. 1, and didn't return to the tour until March. Venus lost six months to a torn abdominal muscle, won consecutive tournaments in April and May, then hurt her left ankle at the German Open in May.

"Obviously the fact their ranking is down there because they haven't played because they've been injured," Mills said. "We're sort of recognizing the fact."

In the men's seedings, the All England Club decided to put Coria at No. 3 even though he is a clay-court expert who has never won a match at Wimbledon. Henman, by contrast, is a grass-court specialist who has reached the semifinals four times.

Mills acknowledged that "many people" would argue that Henman deserves to be seeded higher than Coria, but he said the decision was based on a formula taking into account ATP tour points on other surfaces as well as grass.